JPH0586108A - Suspension polymerization method - Google Patents

Abstract

PURPOSE:To easily obtain transparent, colored particles having proper particle diameters and a narrow particle diameter distribution by incorporating an oil- or water-soluble dye into a dispersed phase comprising a monomer mixture and conducting suspension polymerization in a specific manner. CONSTITUTION:A monomer mixture serving as a dispersed phase and an aqueous medium serving as a continuous phase are stored in separate tanks 2 and 1, respectively. The monomer mixture and the aqueous medium are continuously fed in a regulated proportion to a dispersing machine 5 through separate lines with constant delivery pumps 4 and 4 to obtain a suspension of polymerizable droplets having desired sizes. The suspension in the dispersing machine 5 is then introduced into a polymerization tank 3, where polymerization reaction is carried out to obtain a polymer. An oil- or water-soluble dye has been incorporated in the dispersed phase. Thus, transparent, colored particles which are homogeneous and spherical can be easily produced through suspension polymerization. A wide range of dyes are usable in this method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidity control agent for controlling the fluidity and gloss characteristics of a space-preserving agent, a slipperiness-imparting agent, a functional carrier, surface-active monodisperse particles, standard particles, toners and paints. It relates to a method for obtaining particles of a polymerized product suitable for use in the particle industry such as fillers, especially particles having a controlled particle size and particle size distribution, especially particles having a particle size of 5 to 50 μm, which are spherical. And an improved process for obtaining transparent colored particles by suspension polymerization.

[0002]

2. Description of the Related Art In recent years, the importance of the particle industry utilizing the function of the particles themselves has been increasing. However, it is known as a field of application for such materials as a gap-retaining agent, a slipperiness-imparting agent, a functional carrier, and a surface-active monomer. At present, in order to obtain particles for use as dispersed particles, standard particles, toners, functional fillers that control the fluidity and gloss properties of paints, etc., by a polymerization method, currently mainly relying on an emulsion polymerization method. Is. However, the emulsion polymerization method is very difficult to remove non-negligible impurities such as an emulsifier, the particle size of the obtained particles is limited, the cost is extremely high, and the manufacturing method is complicated and unsuitable for mass production. It has a narrow particle size distribution and 1 μm
There is a problem that it is extremely difficult to obtain particles of the above size. In emulsion polymerization, since the continuous phase of the monomer (dispersed phase) is dissolved during the reaction process, the colorant is hardly taken into the product particles. Further, the dye generally has a chemically active group, and therefore, in this process, the dye is easily attacked by a radical active species of the polymerization reaction and easily causes discoloration or fading.

On the other hand, in the suspension polymerization method, the product obtained is in the form of particles, but only those having a non-uniform particle size and a wide particle size distribution are obtained, which is the mechanical property of the polymer. Improvements are desired because they have important relationships with properties such as strength, chemical resistance, hue, transparency, and moldability. When the transparent colored fine particles are obtained by the suspension polymerization method, the dye to be used is limited to the oil-soluble dye, and the water-soluble dye has a problem that it cannot be sufficiently colored by being dissolved in water during stirring. It was a thing. However, for example, a red dye is mainly composed of a water-soluble dye, so that when the suspension polymerization method according to the prior art is applied to obtain transparent colored fine particles, there is a problem that the selection range of the dye of any hue is narrow. It was something to raise.

[0004]

An object of the present invention is to provide a means for easily producing homogeneous and spherical transparent colored particles by a suspension polymerization method, and to use a wide range of dyes to be selected. It is to provide a manufacturing method of.

[0005]

The present invention has been made to achieve the above object as a result of intensive studies, and its outline is as follows. The present invention, a dispersed phase consisting of a monomer composition, and a continuous phase consisting of an aqueous medium, each held in an independent tank, and through each independent path,
Continuously supplying both to the granulator at a controlled ratio to obtain a suspension having polymerizable droplet groups of a desired size,
In the suspension polymerization method, which comprises taking out the suspension from the granulator and introducing it into a polymerization tank to complete the polymerization reaction to obtain a polymer, an oil-soluble or water-soluble dye is added to the dispersed phase. It is a suspension polymerization method characterized by containing.

The suspension polymerization method of the present invention will be described below with reference to the drawings (FIGS. 1 and 2). First, as shown in FIG. 1, a continuous phase tank 1 containing a continuous phase and a dispersed phase tank 2 containing a dispersed phase.
Are simultaneously introduced into the granulator 5 at a constant ratio through the metering pumps 4 and 4, respectively, and a shearing force is applied thereto to discharge the suspension as a suspension, and the polymerization tank 3 equipped with the condenser 6
Then, the heating jacket 7 provided around the polymerization tank 3 performs necessary heating to complete the polymerization reaction to produce a product having a small particle size and a uniform particle size distribution. In the present invention, in this case, in particular, an oil-soluble or water-soluble dye is put in the dispersion phase tank 2 to obtain homogeneous and spherical colored particles which could not be obtained by the prior art.

An example of the granulator 5 used in the present invention is as shown in FIG. 2, and the granulator 5 has a dispersed phase supply port 1
4 and a continuous phase feed port 13, both liquids enter the shear region 11. A stirring blade 10 is provided in the shear region 11 by the rotating shaft 8.
Is fixed. The stirring blade 10 is rotated by the rotating shaft 8 to generate a suspension in the shear region 11 by a shearing force.
A discharge control gap 12 is provided at the edge of the shear region 11, and the dispersion liquid (suspension liquid) passing through this gap is discharged from the upper dispersion liquid discharge port 9 and guided to the polymerization tank 3. It is designed so that it can be eaten.

In the present invention, the dispersed phase is formed by the monomer composition and the oil-soluble or water-soluble dye. As the monomer composition used in the present invention, for example, the following polymerizable polymerizable monomers can be used.
For example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p
-Phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-
Butyl styrene, pn-hexyl styrene, pn-
Octyl styrene, pn-nonyl styrene, pn-
Styrene and its derivatives such as decyl styrene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, etc .; vinyl acetate , Vinyl propionate, vinyl benzoate, and other organic acid vinyl esters; methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, methacrylic acid. Methacrylic acid and its derivatives such as 2-ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; acrylic acid, methyl acrylate, ethyl acrylate, acrylic acid - butyl, isobutyl acrylate,
Acrylic acid and its derivatives such as propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinyl methyl ether, vinyl ethyl ether, Vinyl ethers such as vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone; N-vinyl pyrrole, N-
There are N-vinyl compounds such as vinylcarbazole, N-vinylisodol and N-vinylpyrrolidone; vinylnaphthalenes; and polymerizable monomers such as acrylonitrile, methacrylonitrile and acrylamide. These monomers are
These may be used alone or in combination of two or more as needed in various compositions.

As the dye that can be used in the present invention, an oil-soluble or water-soluble dye that exhibits solubility or dispersibility in the above-mentioned monomer can be used. For example, as oil-soluble dyes, oil yellow 2G, oil yellow BB, oil yellow N, oil yellow AB, oil yellow O
There are dyes such as B, Fat Orange R, Oil Orange R, Orient Oil Red RR, Eisen Oil Red XO, Indoline, Organo Blue G and Oil Blue GA. As water-soluble dyes, Direct Brilliant Yellow G, Quinoline Yellow KT, Direct Pure Yellow 5G, Direct Fast Yellow GG, Direct Fast Yellow BC, Direct Orange R, Solar Discharge Orange GL, Sirius Supra Orange 3GLD, Direct Corinth G, Direct Fast Scarlet 4BS, Benzo Red 8B
S, Congo-Red, Direct Scarlet B, Sirius Pink G, Sirius Red BB, Sirius Scarlet B, Direct Violet N, Direct Violet O, Direct Deep Black RW, Direct Black HW, Direct Black EX, Benzo Fast Copper Black RL Etc. are applicable to the present invention.

On the other hand, the continuous phase is formed by a continuous phase component composed of an aqueous medium. The continuous phase preferably contains a suspension stabilizer. The suspension stabilizer used in the present invention is often a water-soluble polymer having a hydrophilic group and a hydrophobic group in its molecule. The suspension stabilizer has a polar group such as a hydroxyl group, a carboxyl group and a salt thereof, a sulfone group and a salt thereof as a hydrophilic group, and is composed of an apolar group such as an aliphatic or aromatic group as a hydrophobic group. The compound having the ability to prevent and stabilize coalescence of the monomer composition particles formed by the granulation step. As such suspension stabilizers, for example, polyvinyl alcohol, casein, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, cellulose derivatives such as ethyl cellulose, starch and its derivatives, poly (meth) acrylic acid and salts thereof are used. ing. In addition, inorganic powders such as calcium phosphate and powdered silica are often used. During the polymerization, these suspension stabilizers serve to coat the surface of the droplets and prevent coalescence and agglomeration of the droplets. It is also possible to add a surfactant such as sodium dodecyl sulfonate or sodium dodecylbenzene sulfonate as an auxiliary agent of the suspension stabilizer.

[0011]

Generally, in the suspension polymerization method, the continuous phase and the dispersed phase are put in the same container, and both are stirred by mechanical force to obtain a so-called suspended state. In this state, the dispersed phase becomes droplets. However, these droplets do not exist stably during the reaction, and particularly in the state where the viscosity of the dispersed phase at the initial stage of the reaction is low, they easily break up and coalesce in the continuous phase medium. Therefore, even if a water-soluble compound is contained in the continuous phase in advance, it is easily eluted into the aqueous phase while repeating this division and coalescence. Therefore, it is difficult to obtain the product particles while the water-soluble compound is contained in the usual suspension polymerization.
In the polymerization apparatus of the present invention, however, both phases are held in separate containers before they are dispersed, so that they do not come into contact with each other. Further, since the dispersion is carried out in an extremely short time and the liquid droplets become stable immediately, even if the water-soluble compound is contained in the dispersed phase, it is hardly eluted into the aqueous phase. In addition, in the present dispersion method, the process in which droplets are generated is due to the splitting of the dispersed phase, and the process of coalescence can be ignored. This point is also a reason for preventing elution into the aqueous phase.

[0012]

EXAMPLES The present invention will be specifically described below based on examples. <Example 1> As a continuous phase, an aqueous solution of polyvinyl alcohol (manufactured by Tokyo Chemical Industry Co., Ltd., polymerization degree: about 2000, saponification degree: about 80%) was prepared in an amount of 1% with respect to water, and sodium sulfate was added with an aqueous solution in an amount of 3% with respect to water. The continuous phase tank 1 shown in FIG. In addition, 4000 g of styrene and 10 butyl acrylate as a dispersed phase
A solution prepared by dissolving 15 g of 2,2′-azobisisobutyronitrile in a mixed solution of 00 g was prepared, and 400 g of a yellow dye (TON-YELLOW manufactured by Mitsui Toatsu Co., Ltd.) was added to the mixed solution.
Was dissolved. This solution was put into the dispersion phase tank 2 shown in FIG. Using the granulator shown in FIG.
Min, continuous phase was fed to the granulator at 400 ml / min for 10 minutes. The granulator was operated at 10,000 rpm. The diameter of the rotating part was 50 mm. The dispersion liquid that passed through the granulator was introduced into the polymerization tank 3 shown in FIG. 1 while being stirred with a turbine-type stirring blade at 300 rpm, and reacted for 8 hours. The polymer composition obtained above was cooled and filtered through a 200-mesh sieve. When this composition was observed with a microscope, it was yellow transparent spherical particles. In addition, FIG. 3 shows the results (number distribution) of the particle size of the above polymer composition measured by using a Coulter counter (aperture 100 μm). The polymer composition had a narrow particle size distribution as shown in FIG. 3 and a mode value of about 7.5 μm.

Example 2 As a continuous phase, an aqueous solution of polyvinyl alcohol (manufactured by Tokyo Chemical Industry Co., Ltd., polymerization degree of about 2000, saponification degree of about 80%) in water of 1% and sodium sulfate in water of 3% was prepared. Was adjusted and placed in the continuous phase tank 1 shown in FIG. Further, a liquid prepared by dissolving 15 g of 2,2'-azobisisobutyronitrile in a mixed liquid of 4000 g of styrene and 1000 g of butyl acrylate as a dispersed phase was prepared, and a red dye (OLL PIN312 manufactured by Orient Chemical Co., Ltd. was added to the mixed liquid. ) 400 g was dissolved. This solution was put into the dispersion phase tank 2 shown in FIG. Using the granulator shown in FIG.
Disperse phase 100 ml / min, continuous phase 400 ml / min 1
Feed to granulator for 0 minutes. The granulator was operated at 10,000 rpm. The diameter of the rotating part was 50 mm. The dispersion liquid that passed through the granulator was introduced into the polymerization tank 3 shown in FIG. 1 while being stirred with a turbine-type stirring blade at 300 rpm, and reacted for 8 hours. The polymer composition obtained above was cooled and filtered through a 200-mesh sieve. When this composition was observed with a microscope, it was red and transparent spherical particles. Further, the particle size distribution of the above polymer composition was measured using a Coulter counter (aperture 100 μm) (number distribution) and the results are shown in FIG. The polymer composition had a narrow particle size distribution as shown in FIG. 4 and a mode value of about 5.5 μm.

<Example 3> As a continuous phase, an aqueous solution of polyvinyl alcohol (manufactured by Tokyo Kasei Co., Ltd., polymerization degree: about 2000, saponification degree: about 80%) in water of 1% and sodium sulfate in water of 3%. Was adjusted and placed in the continuous phase tank 1 shown in FIG. A solution prepared by dissolving 15 g of 2,2′-azobisisobutyronitrile in a mixed solution of 4000 g of styrene and 1000 g of butyl acrylate as a dispersed phase was prepared, and a blue dye (BLUE2000 manufactured by Mitsui Toatsu Co., Ltd.) was added to this mixed solution. ))
100 g was dissolved. This solution was put into the dispersion phase tank 2 shown in FIG. Using the granulator shown in FIG.
The continuous phase was fed to the granulator at 0 ml / min for 10 minutes at 400 ml / min. The granulator was operated at 10,000 rpm. The diameter of the rotating part was 50 mm. The dispersion liquid that passed through the granulator was introduced into the polymerization tank 3 shown in FIG. 1 while being stirred with a turbine-type stirring blade at 300 rpm, and reacted for 8 hours. The polymer composition obtained above was cooled and filtered through a 200-mesh sieve. When this composition was observed with a microscope, it was blue transparent spherical particles. In addition, the particle size of the above-mentioned polymer composition is measured by a Coulter counter (aperture 100 μ
The result (number distribution) measured using m) is shown in FIG.
The polymer composition had a narrow particle size distribution as shown in FIG. 5 and a mode value of about 6.0 μm.

<Comparative Example 1> Dodecylbenzene sulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) as a continuous phase was added to water in an amount of 0.1.
%, Sodium sulfate 3% with respect to water was prepared, and the same procedure as in Example 1 was carried out except that the solution was placed in the continuous phase tank 1 shown in FIG. This reaction system is an emulsion polymerization method. In this example, the dispersion system became unstable during the polymerization reaction, the continuous phase was wrapped around the stirring blade, and the polymerization reaction did not proceed sufficiently to obtain a product.

Comparative Example 2 Dodecylbenzene sulfonic acid (manufactured by Tokyo Kasei Co., Ltd.) as a continuous phase was added to water in an amount of 0.1.
%, Sodium sulfate 3% with respect to water was prepared, and the same procedure as in Example 2 was carried out except that the solution was placed in the continuous phase tank 1 shown in FIG. This reaction system is an emulsion polymerization method. In this example, the dispersion system became unstable during the polymerization reaction, the continuous phase was wrapped around the stirring blade, and the polymerization reaction did not proceed sufficiently to obtain a product. Further, most of the red dye was eluted in the continuous phase, and the polymer wrapped around the stirring blade was hardly colored.

[0017]

EFFECTS OF THE INVENTION According to the present invention, microscopic droplets are generated by the strong shearing force, crushing, impact, and turbulent force generated in the shearing region, and the droplets leave the shearing force field. 5 to 50μ because it becomes minute dispersed particles due to the discharge control gap at the time of
Transparent colored particles having a moderate particle size and a sharp distribution of m 2 can be obtained. Further, it is possible to provide a method for producing transparent colored particles in which the selection range of the applied coloring dye is wide.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a polymerization apparatus used in the present invention.

FIG. 2 is an explanatory view showing an example of a granulator used in the present invention.

[Figure 3]

[Figure 4]

FIG. 3 to FIG. 5 are graphs showing the particle size distributions of the polymer compositions of Example 1, Example 2 and Example 3, respectively.

[Explanation of Codes] 1 Continuous phase tank 2 Dispersion phase tank 3 Polymerization tank 4 Metering pump 5 Granulator 6 Condenser 7 Heating jacket 8 Rotating shaft 9 Dispersion liquid discharge port 10 Stirring blade 11 Shearing area 12 Emission control gap 13 Continuous phase supply port 14 Dispersed phase supply port

Claims (1)

[Claims] 1. A dispersed phase composed of a monomer composition and a continuous phase composed of an aqueous medium are held in independent tanks, respectively, and both are continuously passed through independent paths at a controlled ratio. Supplying to a granulator to obtain a suspension having polymerizable droplet groups of a desired size, and removing the suspension from the granulator and introducing it into a polymerization tank to complete the polymerization reaction. A suspension polymerization method comprising a step of obtaining a polymer by a method of obtaining a polymer by adding an oil-soluble or water-soluble dye to the dispersed phase.